Shield forming and mounting method and apparatus



July 1, 1958 F. J. GRUBE ETAL 2,840,886

SHIELD FORMING AND MOUNTING METHOD AND APPARATUS Filed NOV. 29, 1952 4Sheets-Sheet 1 Invervtors: Fr'edevick J. Gr-ube, John H.HoLLopel:Te,

b5 W 5 K Theiv A k kovnea.

y 1958 F. J. GRUBE EIAL 2,840,886

SHIELD FORMING AND MOUNTING METHOD AND APPARATUS Filed Nov. 29, 1952 4Sheets-Sheet 2 Figz.

Inven lqors: I Frederick J.G1-ube, John Hfiottope kve, b8 W (V A/ TheirA t bovneg.

y 1 F. J. GRUBE ETAL 2,840,886

SHIELD FORMING AND MOUNTING METHOD AND APPARATUS Filed Nov. 29; 1952 4Sheets-Sheet 3 as 36 5 I I a9 92 94 95 4/ I I v I 40 o ""fi 29 96 as vI. T p 42 r 47 5 4 I 80 54 lr ven tors.

- Fredemck d. Gvube,

John H.Hol,l opekTe, 10 W K Their A t' b'or E-J' y 1953 F. J. GRUBE ETAL2,840,886

SHIELD FORMING AND MOUNTING METHOD AND APPARATUS Filed Nov. 29, 1952 4Sheets-Sheet 4 Figs Invervtovs: Fvedevick d. Grubs, John H.HoLLopetr*e,

by M5 X Then AbtoT-ne5.

United States Patent SHIELD FORMING AND MOUNTING METHOD AND APPARATUSFrederick J. Grube, East Cleveland, and John H. Hollopetre, MayfieldHeights, Ohio, assignors to General Electric Company, a corporation ofNew York Application November 29, 1952, Serial No. 323,212

6 Claims. (Cl. 29--25.13)

Our invention relates to a method of and apparatus for automaticallyforming and mounting sheet metal shields or anodes constituting part ofthe internal electrode structure of electric lamps and similar devices.

It is an object of our invention to provide a method and automaticapparatus for forming a blank of sheet adapted for use in combinationwith an automatic mount making machine of the type disclosed in theapplication of L. E. Dilts Serial No. 323,315, filed of even dateherewith and assigned to the same assignec as this application, nowPatent No. 2,781,796 granted Feb. 19, 1957.

Another object of our invention is to provide apparatus capable ofextensive uninterrupted periods of use in the forming and the mountingof generally cylindrical metal shields or anodes, and at low cost andwith a minimum of attention.

Another object of our invention is to provide a method and apparatus forforming, from blanks cut from a ribbon of metal, shields or anodeshaving an accurately formed main portion of generally cylindrical shapeand having an accurately formed corrugation along one side suited toslip snugly over a wire lead of a mount and be crimped to the lead. Afeature of our invention is the formation of the corrugation from thecenter or medial portion of the blank by means of a die which forms saidcenter portion about a ridge extending the length of a mandrel, followedby wrapping of the remainder of the blank around the mandrel byadditional die members. A shield or anode so formed maintains its shapein both the corrugation and the main portion thereof so that it can bemounted at a definite position upon the wire lead of a mount and in adefinite relation to the cathode thereof. The shield or anode also has astiffness normally associated with more complex and costly shields oranodes even though the ends of the blank from which it is formed lie atan abutting. or overlapping relation and are not normally fastenedtogether. Another object of our invention is to provide apparatus foreffecting both the removal of the-shield or anode from forming apparatusand the transfer of said shield or anode to proper relation to the leadand cathode of a mount by relatively simple means which because of itsconstruction is adapted to extended periods of satisfactory and troublefree operation.

One embodiment of our invention provides for a spooled supply of metalribbon to be fed end-foremost past one side of a mandrel and the shieldto be formed from an end portion of the ribbon by dies cooperating withsaid mandrel. The sequence of operation of the dies is such that one diefirst moves to clamp the adjacent end portion of the ribbon to themandrel, then effects the shearing of said end portion to form a blank,and then presses said blank to the shape of the mandrel. Thisfirst-mentioned die also forms a corrugation across one dimension of theblank intermediate its ends, which corrugation is used to attach theshield to a mount. To this end, there are provided a matching groove andridge in the meeting faces of the die and the mandrel, respectively.Other dies bend the ends of the blank extending on opposite sides of thefirst-mentioned die around the mandrel to either an abutting or aslightly overlapping relation. A shield made by this apparatus isaccurately formed and stiff although the metal ribbon from which it ismade is of iron or nickel in the order of .005 to .010 inch in thicknessand the ends are not normally locked together in any way.

The transfer of the shield which takes place in the next step in theoperation of the preferred form of apparatus provides for the shield tobe forced off the end of the mandrel and, in the course of saidoperation, pushed end foremost over a lead and a cathode of a mount.Immediately following the transfer, the shield is permanently combinedin the mount structure by a pair of jaws which crimp the corrugation ofthe shield and the enclosed lead so as to fasten them securely together.

Further features and advantages of our invention will appear from thefollowing detailed description of a preferred embodiment illustrated inthe accompanying drawings.

In the drawings:

Fig. l is a side elevation of a shield forming and mounting apparatuscomprising the invention, said apparatus being arranged at operativerelation to a mount for a fluorescent lamp.

Fig. 2 is a plan view of the shield forming and mounting apparatus withthe clamping jaws and other portions broken therefrom to shownunderlying parts more clearly.

Fig. 3 is an elevation of the shield forming and mounting apparatus atright angles to Fig. 1 and showing in particular the operating means,the metal ribbon feed control and crimping means.

Figs. 4, 5, 6 and 7 are fragmentary plan views, on a end portions of theshield forming mandrel and the shield stripper at their initialoperative position with respect to a lamp mount and at the moment acompletely formed shield on said mandrel is about to advance over saidmount by movement of the stripper.

The shield forming and mounting apparatus shown in the'drawing isadapted to automatically repeated cycles of operation and to that end'issuited to operate at one work station of an automatic mount makingmachine. When incorporated in such a machine, the apparatus is mountedupon a table 1 at one work station along an indexing conveyor 2 (onlypartly shown) for advancing the mounts 3, and it is operated by a driveshaft 4 (Fig. 3) located below the table 1 and rotating in synchronismwith the movements of the conveyor 2.

The feeding of sufiicient material to constitute a blank for the shieldis effected by advancing the metal ribbon 5, already threaded throughsaid apparatus, in a rightto-left direction (Figs. 1 and 2). The mainsupply of the metal ribbon 5 is contained upon a spool (not shown) at afixed position to one side of the apparatus and is in the form of a bandof metal, usually nickel or iron, of the correct width for the shieldsand in the order of .005 to .010 inch thick. The advancement of theribbon is produced upon movement of the feed slide 6 within horizontalways in the main supporting frame 7 of the apparatus and said slide 6and ribbon 5 are moved together by a dog 8. The slide 6, which islocated in ways below the cover plate 9, is moved together with theribbon 5 when the roller 10 on the outer end of the dog 8 is moved bythe lever 11 to pivot the dog 3 sufficiently about the pivot pin 12 tocause it to first grip the ribbon 5 between its toe and the upstandingadjacent wall of the slide 6, and to then move bodily to carry theribbon and slide forward. Other parts of the ribbon feeding meanscomprise an operating arm 13 located adjacent lever 11 on the pin 14extending from the side of the frame 7; a vertical operating rod 15located to one side of the center of the apparatus; and a connecting bar16 joining the operating rod 15 with a vertically movable hollow core 17within the center of the frame 7. These parts operate during an intervalin which the hollow core 17 is being moved downward under the control ofthe main operating means located below the table 1 and associated withthe main drive shaft 4 and produces a corresponding downward motion inthe operating rod 15 because of the solid connection formed therebetweenby the bar 16. The operating rod 15 slides vertically in the bearingsprovided by portions of the frame 7 in engagement with the ends thereofand causes the upper nuts 18 to turn the arm 13 counterclockwise aboutthe pin 14 so that the helical spring 19, which joins posts in arm 13and lever 11, turns said lever 11 correspondingly. At the limit of thefeeding motion, the lever 11 bears against the stop screw 20, and thespring 19 is expanded by the continuing movement of the arm 13.

The advancement of the metal ribbon 5 pulls additional material from thespooled supply between a pair of guide rolls 21 on a bracket 22 attachedto one side of the frame 7 and between the alternately positionedrollers 23 farther along said bracket 22, which rollers 23 function as aconventional type of straightener. The forward end of the metal ribbon 5is advanced through a slot (Fig. 4) formed by an undercut in one block25 of the pair of stationary blocks 24 and 25 (Figs. 2 and 4) at themouth of the Ways in frame 7 for the slide 6, and thence along a guidingface 26 (Fig. 10) in the otherwise cylindrical stripper 27 to a positionadjacent the side of the mandrel 28. The forward end of the ribbon 5 andthe immediately adjacent parts of the apparatus then appear as shown inFig. 4.

The next operation of the apparatus causes the endmost portion of theribbon 5 to be gripped between the face of the die 29 and thelongitudinal ridge 30 along the immediately adjacent side of the mandrel28, and further causes said endmost portion, which is to be made intothe shield, to be sheared from the remainder of the ribbon 5 by themovement of the knife edge 31 of said die 29 across the knife edge 32 ofblock 24. Also included in this step in the operation of the apparatusis the advance of the die 33 toward'the mandrel 28 to the extent thatthe screw 34 thereon bears against the side of the below the paths ofmovement thereof and will not interfere with the travel of said dies 29and 33 to proper relation to the mandrel 28. One other movement is alsoincluded in the presently described operative step, said movement beinga further advance of the die 29 which bends the severed blank portion 35of the metal ribbon 5 to the extent shown in dot-dash lines in Fig. 5wherein said blank 35 is caused to be bent part way around the ridge 30on the mandrel 28 and into engagement with each side thereof.

Both dies 29 and 33 are correspondingly arranged in horizontal slideways in the top portion of the frame 7 in which they are held by thecover plates 36 and 37, respectively, and are caused to take theirrespective motions by the upward motion of cam slides 38 and 39 (Fig. 3)extending upward through slotted outer end portions of the frame. Asshown in connection with die 29 and slide 38, the die 29 is displaced byan inclined portion of a cam track 40 engaging a roller 41 fixed uponthe die 29. Operating means for the slides 38 and 39 in turn, isprovided in the main actuating mechanism located below the table 1 andon the lower portion of the frame 7 which retains said slides 38 and 39in vertical slide ways behind the cover plate 42 and the bracket 43,respectively. The holding, shearing, and bending motions of the die 29are the result of an upward movement of a platform or collar 44 to whichthe cam slide 38 is connected by the linkage 45, and occur when thelever 46 is moved appropriately through its engagement with the cam 47on the drive shaft 4. The platform 44 is slid vertically upon acylindrical lower end portion 48 of the frame 7 and is connected to thelever 46, in a manner to prevent rotation with respect thereto, by thelinks 49, 49. Motion of the lever 46 is about'the pivot shaft 50 inaccordance with the shape of a track in one face of the cam 47 andengaged by the roller 51. The motion of the opposite die 33, on theother hand, is the result of an upward movement of the. end of the lever52 of the operating means, to which the cam slide 39 is at tached by thelinkage 53, and is determined by the change in position of portions of atrack in the face of the cam 54 on drive shaft 4 and engaged by a roller55 on said lever 52. In order to avoid the possibility of the die 33 orthe screw 34 thereon being pressed against the mandrel 28 withsufiicient force to push it from proper alignment in the apparatus, saidscrew 34 is adjusted to engage the mandrel 28 while the face of the die33 is still spaced a distance equal to the thickness of the metal ribbon5 therefrom, and a stop for the movement of the die 33 is provided by ascrew 56 (Fig. 2) which projects into a cross slot 57 of limited lengthin the top of said die 33. The screw 56 has an eccentric lower end andcan be turned within the cover plate 37 to a position where it isengaged by the end wall of the slot 57 when the proper movement in thedie 33 has taken place. The excess motion of the operation is thenabsorbed in the linkage 53 (Fig. 3) by the upward movement of the end ofthe rod 58 into the sleeve 59 and the compression of the helical spring60 butting against the nuts 61 on a lower portion of the rod 58. A pin62 extending through the end of the rod 58 and into slots in oppositesides of the sleeve 59 prevents the linkage 53 from separating when .thedie.33 and the slide 39 are free to move in either direction.

The next operations to occur in the apparatusrare advancing movements ofthe dies 64 and 65 located at opposite sides of the mandrel 28 (Fig. 4)to positions nearer said mandrel 28 and adjacent the ends of the blank35 as shown in Fig. 5 so that said ends are prevented from springingoutward into the path of movement of the faces of the dies 64 and 65 inthe immediately following interval when the die 29 completes its fullmotion toward the mandrel 28. The movements of the dies 64 and 65, whichare located in horizontal ways below the cover plates 66 and 9,respectively, in'the frame'7, are produced g in a manner correspondingto that effecting movement in die 29 by vertically arranged cam slides67 and 68 located in slotted rear portions of the frame and movedvertically with respect thereto in ways in the frame 7 behind the coverplate 7a and bracket 22. Rollers (not shown) fastened to the dies 64 and65 ride in cam tracks (also not shown) in the slides 67 and 68,respectively, to actuate said dies 64 and 65. The slides 67 and 68 areconnected at their lower ends to platform 44 of the operating means ofthe apparatus by the linkages 69 and 70 which correspond to the linkage53 associated with the slide 39 and die 33, and at the present momentconvert the motion of said platform 44 into motion in the dies 64 and65. All portions of the apparatus are now properly located forcontinuation of the forming of the blank 35.

A succession of movements occurring in the dies 29, 33, 64'and 65 nowhas the effect of wrapping the ends of the blank 35 around the mandrel28. This succession of movements, as are all movements of the apparatus,are produced very rapidly without appreciable interruption in thecontinuous operation of the apparatus and are introduced by a furtheradvance of the die 29 causing said blank 35 to be formed around theridge 30 and the immediately adjacent side portion of said mandrel 28 bythe arcuate face portion 29' and the slot 30' which corresponds in shapeto the ridge 30. The apparatus and the blank 35 then appear as shown infull lines in Fig. 5, the blank having a corrugation 63 extending thefull width thereof. The die 33 is now withdrawn from its positionagainst the mandrel 28 as shown in Fig. 6 so as to provide clearance forthe ends of the blank 35, and the arcuate faces 64' and 65 of dies 64and 65 are simultaneously closed on said mandrel 28 to force additionalportions of the blank 35 into conformity with the said mandrel 28. Thefinal bending operation occurs when the die 33 is again advanced towardthe mandrel 28 to cause its arcuate face 33' to press the ends of theblank 35 thereagainst. In certain instances, the ends of the blank 35will be in abutting relation; however, it is preferable to adjust theapparatus so that one end of the blank is slightly longer than the otherand said longer end is caused to overlap said other end as shown in Fig.7. The dies 33, 64 and 65 force the blank 35 tightly against the mandrel28 in every instance regardless of any variation in the blank 35, sinceexcessive motion is provided in the operating means for said dies 33, 64and 65 and provision is made in the linkage 69 and 70 for absorbing theover travel of said means.

The shield 71 (Fig. 7) is now completely formed and will continue to hugthe mandrel 28 when in the succeeding operations of the apparatus allfour dies 29, 33, 64 and 65 are withdrawn by the downward motion of thecam slides 38, 39, 67 and 68, respectively, under the control of theoperating means. The separation operation, of which the retraction ofthe dies 29, 33, 64 and 65 is a part, also includes immediatelyfollowiog operations which both eject the shield 71 from said apparatusand, in the course of so doing, advance it end foremost over the cathode72 and the longer lead 74 of the two leads 73 and 74 of the mount 3(Fig. to proper mounting relation thereto.

The relative positions of the mandrel 28 and the mount 3 are such thatthe mandrel 28 is directly in alignment with the cathode 72, and isorientated so that the ridge 30 and, accordingly, the corrugation 63 isaligned with the lead 74 paralleling one side of said cathode 72. Thearrangement of the mandrel 28 and mount 3 makes it possible for theshield 71 to be transferred to said mount 3 by the normal upward motionof a stripper 27 which is moved up over the mandrel 28 to an extentsufficient to push said shield 71 from said mandrel 28 and to the properelevation with respect to the mount 3. The

mandrel 28 as shown in Fig. 1 is a stationary element of the apparatusin. that it is attachedto an end of a rod 75 located within the hollowinterior of the stripper 27 and: the hollow core 17, and in that thelower end of the rod 75 is anchored by a transverse pin 76 retained by alower portion of the frame 7 and extending through clearance slots 77 inthe walls of the hollow core 17. The stripper 27, on the other hand, isattached to the upper end of the hollow core 17 and has the verticalmovements introduced therein by the operating means of the apparatus inengagement with the lower end thereof beyond the lower end 48 of theframe 7. The hollow core 17 is attached by the adjustable link 78 to thelever 79 of the operating means and is moved by the motions of the lever79 about the stationary pin 80 in accordance with the advance of variousportions of the track in the back face of cam 47 into engagement with aroller 81 on said lever 79.

Although the shield 71 is in part maintained in proper alignment withthe mount 3 dining its transfer by the engagement of the open interiorof the corrugation 63 with the lead 74, it is also guided by the passageof the cylindrical main portion thereof up between the guide blocks 82and 83 (Figs. 8 and 9) on the jaws 84 and 85 of the shield attachingmeans. The jaws 84 and 85, which are located upon the pivot pins 86 and87 projecting beyond the frame 7 at positions on opposite sides of thedie 33, are in a partly closed position because of the timed operativefunctions of a toggle arrangement engaging the pins 88 and 89 in theouter ends thereof and under the control of operating means below thetable 1. The force of the toggle-joint is against the constantjaw-opening influence of the helical spring 98 (Fig. 3) joining thelower ends of the pins 88 and 89 and is applied against said pins 88 and89 by the links 91 and 92, respectively, when the center pin 93, theconnecting block 94, the ear 95 and-the upperend of the lever 96 aremoved toward the jaws 84 and 85. The lever 96 transforms the verticalmotion of the rod 97, extending to the operating means, by its motionabout the pivot pin 98 in the bracket 43 and is actuated by motion ofthe lever 99 of said operating means about the 'shaft 50 under theinfluence of a roller 100 in engagement with a track in the back face ofcam 54.

More accurate location of the main cylindrical portion of the shield 71occurs when the guide blocks 82 and 83 are closed further by the motionof the jaws S4 and 85 which motion is primarily effected to crimp thecorrugation 63 onto the lead 74 of the mount 3. This latter motion ofthe jaws 84 and 85 is produced by still further motion of the lever 96and the operating means and causes the serrations 101 in the coactingfaces of the jaw ends 102 and 103 to close on the shield corrugation 63so as to indent and otherwise bend said corrugation 63 and the lead 74sufficiently to bind them together. The serrated faces of the jaw ends102 and 103 are angled toward each other at the edge adjacent thecylindrical portion of the shield 71 so that the corresponding portionof the corrugation 63 is indented more deeply and so that the lead 74 isforced into and locked in the base of said corrugation 63. Matchingportions 104 above and below the serrations in the faces of the jaw ends102'and 103 seat against correspondingly located portions of thecorrugation 63 at the limit of motion, which is determined by theseating of a portion of the link 92 against the bolt in an upstandingportion of bracket 43, and keep it and the lead 74 from being bent outof alignment. At the conclusion of the crimping operation the finalfunction of the mounting of the shield 71 on the mount 3 is completedand such remaining operations in the cycle as have not been describedand relate only to the return of the jaws 84 and 85 to their originalposition, occur. The return of the jaws 84 and 85 is effected by thereturn movement of the togglejoint under the control of operating meansand separates all portions of said jaws 84 and 85 widely so that thecompleted mount can pass from operative relation there 7 to and so thatanothermountS can be advanced to operative relation thereto. During thepast interval, the stripper 27 is lowered and the next cycle ofoperation is started by the feeding of another portion of the ribbonupon downward motion of the hollow core 17.

Another undescribed return motion occurred within the apparatus prior tothe attachment of the shield 71 to the mount 3, said return operationbeing the retraction of the ribbon feeding slide 6 to a position toagain advance the ribbon 5. This particular return operation is broughtabout by the upward movement of the hollow core 17 when the stripper 27is caused to function and the resulting corresponding motion in theoperating rod and clockwise motion of the operating arm 13. The fullmotion of the operating rod 15 is not taken by the operating arm 13inasmuch as the contraction force of the spring 19 is not suflicientlypowerful to turn said arm 13 when the nuts 18 are carried fromengagement therewith and it does not move until the corresponding nuts106 further along the rod 15 engage said arm 13. The position of thenuts 18 and 106 determines the amount the operating arm 13 will bereturned and to a certain extent determines the amount of ribbon 5 thatwill be fed. In the return movement of the operating arm 13, the screw197 thereon engages the edge of lever 11 and turns it to the extent thatit is brought against the stop screw 108 on the frame 7. The return oflever ll, in turn, swings the feed dog 8 about the pin 12 to a positionoutward from the ribbon 5 and against the stop pin 109 in the slide 6 sothat the pressure of lever Iii shifts the feed dog 8 and the slide 6 asa single unit. The ribbon 5 must not move back with the feed slide 6inasmuch as the bite measured off the ribbon 5 by the return movementrepresents the amount of ribbon 5 which will be fed by said slide 6 inthe next cycle of operation. To prevent any such return motion of theribbon 5, a clutch in the form of a roller 1.19 (Fig. 4) in a taperingpocket 111 in the block is provided opposite the forward end thereof.Portions of a spring 112 coiled around a pin 113 retained by the block25 and bearing against the walls of the pocket ill and said roller pressthe said roller 110 against the ribbon 5 and into the narrow part of thepocket 111 so that any back movement of said ribbon 5 is prevented bywedging of the roller 110 against it.

In the normal use of the shield forming and mounting apparatus withautomatic mount making apparatus, it is often desirable for one or morecycles of operation to be skipped in order to avoid the feeding of ashield when a mount is not fed to operative relation to said shieldforming and mounting apparatus or when an improperly constructed mountis fed to said apparatus. Under normal conditions an electrical controlcircuit is maintained to the solenoid 114 (Fig. 3) which circuit causesthe solenoid 114 to tilt the lever 115 about the pivot pin ilo so thatthe stop plunger 117 is pulled back into a portion of bracket 22 and isout of the path of movement of the stud 119 on the operating lever 11 ofthe ribbon feeding means. However, should conditions be such that thecycle of operations of the forming and mounting apparatus is to beskipped, the control circuit will be interrupted by feeler means (notshown) arranged to detect the absence of a mount or the presence of adefective mount in the holder 2 just prior to its arrangement atoperative relation to said apparatus and at a time when the ribbonfeeding means thereof starts the cycle of operations. Undertheseconditions the stop plunger 117 will be moved to the position shown, bytl e expansion force of the helical spring 118 behind the head endthereof and said head end will wedge itself against the conical head ofthe stud 119 so that the operating lever 11 cannot move. The pressure ofthe spring 118 is sufficiently strong to advance the plunger 117 underthe resistance of motion in the lever 115, which bears against thecollar 120 on an end por on o s d plu er 1 in the nk 12 and in thearmature 122 of the solenoid 114 and to wedge the head end-of theplunger 117 against the stud 119 so as to prevent creeping'of thefeeding means during idle cycles.

Although a preferred embodiment of our invention has been disclosed itshould be understood that the invention is not limited to the specificconstruction or arrangement of parts shown, but may be widely modificdwithin the spirit and scope of the invention as defined by the appendedclaims.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

l. Themethod of forming and mounting a shield on a lamp mount comprising'a stem having a pair of lead wires of different lengths extendinglongitudinally therefrom on opposite sides of the axis of the stem andwith their ends bent. laterally inwards to the said axis and supportingtherebetween a filament substantially in alignment with said axis, whichmethod comprises shaping a rectangular sheet metal blank by forming acorrugation across one dimension of the blank intermediate its ends andforming the remainder of the blank to a generally cylindricalconfiguration about an axis parallel to said corrugation, and assemblingthe shield so formed with said lamp mount by aligning the shield axiallywith the mount stem and with the corrugation thcrconaligned with thelonger one of said pair of lead wires and its laterally bent end andeffecting relative axial movement between the shield and mount to bringthe filament within the shield and the said longer lead wire within thecorrugation, and then crimping the said corrugation about said longerlead wire.

2. The method of forming and mounting a shield on a mount having acathode and a lead wire extending therefrom in substantially parallelrelation with the outer end of the lead wire bent over laterally tosupport the cathode, which method comprises holding the mount with thecathode adjacent to and in axial alignment with a mandrel and with thelead wire and its laterally bent end in longitudinal alignment with alongitudinal ridge on a side of said mandrel, placing a rectangularsheet metal blank against said ridge to extend laterally of said mandreland approximately equidistantly to both sides thereof and forming thesheet metal blank around and in conformity with said mandrel and theridge thereon to form a tubular shield having a longitudinal corrugationthereon, sliding the shield axially off the mandrel and around thecathode with the corrugation enclosing the said lead wire after itslaterally bent end has passed through, and securing the shield byaflixing its corrugation to said lead wire.

3. Apparatus for forming electrode shields and securing them toelectrode mounts comprising a mandrel having a longitudinally extendingridge along one side thereof, means to introduce a generally rectangularsheet metal blank into operative relation to said mandrel with the blankadjacent to said ridge and extending transversely thereacross,cooperating die means arranged to wrap said blank around said ridge andaround theremainder of said mandrel to form a tubular shield having alongitudinal corrugation thereon, holder means arranged to be inlongitudinal alignment with said mandrel and to hold a mount with a leadwire thereon in longitudinal alignment with the ridge on said mandrel,stripper means arranged in juxtaposition to said mandrel to push theshield longitudinally off said mandrel toward said holder means toenclose said lead wire in said corrugation, and means mounted adjacentsaid mandrel for securing the shield by its corrugation to said leadwire.

4. Apparatus for forming electrode shields and securing them toelectrode mounts comprising a mandrel having a longitudinally extendingridge along one side thereof, ribbon feeding means located adjacent saidmandrel and arranged to introduce a sheet metal ribbon into operativerelation to said mandrel with an end portion thereof adjacent to saidridge and extending transversely thereacross, cooperating die meansincluding means for severing said end portion to form a blank and meansarranged to wrap said blank around said ridge and around the remainderof said mandrel to form a tubular shield having a longitudinalcorrugation thereon, holder means arranged to be in longitudinalalignment with said mandrel and to hold a mount with a lead wire thereonin longitudinal alignment with the ridge on said mandrel, stripper meansarranged in juxtaposition to said mandrel to push the shieldlongituditudinally off said mandrel toward said holder means to enclosesaid lead wire in said corrugation, and means mounted adjacent saidmandrel for securing the shield by its corrugation to said lead wire.

5. Apparatus for forming electrode shields and securing them toelectrode mounts comprising a mandrel having a longitudinally extendingridge along one side thereof, a stripper member movable longitudinallyover the mandrel and having a guiding face substantially nor mal to theplane of said ridge and tangential to its Outer edge, ribbon feedingmeans located adjacent said mandrel and arranged to feed a sheet metalribbon across the guiding face of said stripper and into operativerelation to said mandrel with an end portion thereof adjacent to saidridge and extending transversely thereacross, cooperating die meansincluding means for severing said end portion of the ribbon to form ablank and means arranged to wrap said blank around said ridge and aroundthe remainder of said mandrel to form a tubular shield having alongitudinal corrugation thereon, holder means arranged to be inlongitudinal alignment with said mandrel and to hold a mount with a leadwire thereon in longitudinal alignment with the ridge on said mandrel,and means operable to eifect sequential actuation of said ribbon feedingmeans, retraction of said stripper member, actuation of said die meanstoward said mandrel to effect the wrapping of the blank therearoundfollowed by retraction of the die means and advancethe mandrel towardsaid holder means to enclose said lead wire in said corrugation, andmeans mounted adjacent said mandrel for clamping said corrugation tosaid lead wire.

6. Apparatus for forming electrode shields and securing them toelectrode mounts comprising a mandrel having a longitudinally extendingridge along one side thereof, means to introduce a generally rectangularsheet metal blank into operative relation to said mandrel with the blankadjacent to said ridge and extending transversely thereacross,cooperating die means arranged to wrap said blank around said ridge andaround the remainder of said mandrel to form a tubular shield having alongitudinal corrugation thereon, holder means arranged to be inlongitudinal alignment with said mandrel and to hold a mount with a leadwire thereon in longitudinal alignment with the ridge on said mandrel,stripper means arranged in juxtaposition to said mandrel to push theshield longitudinally ofi said mandrel toward said holder means toenclose said lead wire in said corrugation, and means mounted adjacentsaid mandrel for securing the shield by its corrugation to said leadwire and comprising jaws having opposed serrated faces and guide blocksmounted on said jaws and having opposing face portions conforming to theshape of the mandrel, and means for closing said jaws to cause the saidblocks to direct the shield into proper alignment with said mount and tocause the said serrated faces to crimp together the said corrugation andthe lead Wire enclosed therein.

References Cited in the file of this patent UNITED STATES PATENTS992,890 Lewis May 23, 1911 1,984,873 Pullman Dec. 18, 1934 2,024,585Laico Dec. 17, 1935 2,264,613 Borton Dec. 2, 1941 2,333,997 Glans Nov.9, 1943 2,442,908 Sirp June 8, 1948 2,515,699 Davidson July 18, 1950FOREIGN PATENTS 624,963 Germany Jan. 31, 1936 1,015,077 France Aug. 27,1952

